Brake mechanism



Aug. 9, 1932. A Y. DODGE I 1,871,407

BRAKE MECHANISM I originalFiled Aug. 24, 1925 v at lglVENTok. I .2 6 BK A TTORNEY Patented Aug. 9, 1932 OF SOUTH BEND, INDIANA, A CORPORATION (OF ILLINOIS E COMPANY,

Original application filed August 24, 1925, Serial No. 51,937. Divided and this application filed July 11,

' 1929. Serial No. 377,393.

This invention relates to brakes and is illustrated as embodied in an internal expanding type of automotive brake.

An object of the invention is to provide a simple positioning means for the brake to predetermine its released position within the brake drum. In one desirable arrangement a floating pivot connecting certain of the frlction elements is contacted, with the brake released, by a lever member fulcrumed at one end to the support plate of the brake and adjustable with respect to said plate by means such as an adjustable eccentric stop mounted in said support plate and contacting the other end of the lever.

While useful also with other brakes, this construction is especially advantageous in determining the inoperative position of a brake of the double-wrapping or shifting anchor type, which anchors at one end when the drum is turning in one direction and at the other end when the drum is turning in the opposite direction.

Other objects and features of the invention will be apparent from the following description of the illustrative embodiment shown in the accompanying drawing, in which:

Figure 1 is a vertical section through the brake just inside the head of the brake drum and showing the brake in side elevation;

F igure'2 is a partial section on the line 2-2 of Figure 1, showing the details of my novel stop; and

, Figure 3 is a view of a modified form be stop lever, the view substantially corresponding to a partial section on the line 3-3 of Figure 2.

The brake illustrated includes a rotatable drum 10, at the open side of which is arranged a suitable backing plate or other support 12, and within which are arranged a plurality of floating double-wrapping interchangeable brake shoes 14 and 16. The shoes are preferably arranged to overlap at their ends and are preferably connected by a pivot 18 having a head 20 slidably engaging support plate 12.

The shoes are forced apart, in applying the brake, against the resistance of a return spring 22 by means shown as a double cam 24. The shoes 14 and 16 constitute a floating friction unit, shoe 14 anchoring on a fixed post 26 when the drumis turning clockwise posts, to permit the described operation and the posts may carry a plate 30 bridging the ends of the shoes and positioning them laterally. The above described structure is shown and described in my co-pending appli- .1;

cation No. 51,937, filed August 24, 1925, the instant case being a division thereof.

The important feature of the invention resides in the novel stop means for determining the idle or inoperative position of the brake shoes. In the preferred embodiment, shoe 16 is held by a spring 32 against an eccentric adjustable stop 34 carried by plate 12. This construction is supplemented by a novel stop comprising a rectangularshaped relatively thin lever member 36 frictionally pivoted at 38 at one of its ends to the plate 12. The radially acting component of spring 32 functions to bodily lift the shoes away from the drum, the head 20 of the pivot pin 18 contacting the lower edge of the lever, the limit of movement of which is determined by a second eccentric adjustable stop 40 mounted in the plate 12 and contacting the other end of the lever. Lever 36 may be straight, as shown in Figure 1, or slightly curved about the axis of the drum, as shown in Figure 3.

In operation, the shoes disclosed, or their equivalent, are pried apart by the cam into drum contact, the wiping action of the latter rotating or bodily moving the shoes in either direction, depending upon the direction of rotation of the drum. The posts 26 and 28 are arranged, as previously; described, to take the thrust of the shoes. With release of the applying pressure of the earn. it is necessary to return the shoes to a position within the drum entirely out of contact therewith to 1 thus obviate what is known as dragging. It is here that my novel invention comes into plav. the combined edect of the springs 22 and 32 serving to move the friction means into contact with the stop pin 34 and lever stop 36. The degree of release movement dewill ' the shoes to the drum in either direction 'of drum rotation for it will be seen that as-the head 20 moves around the drum it will con tact the lever to effect a wedging action of the head between the lever and drum. This action is not present with the construction of Figure 3, inasmuch as the lower edge of the lever forms an arc of a circle, the center of which coincides with the axis of the drum.

A very simple and efiective stop-is thus provided, preferably, though not necessarily, positioned diametrically opposite the cam. It will also be obvious that my novel stop structure is especially. applicable to contact any suitable projection on any type of friction means, the released position of which is to be determined.

While one illustrative embodiment has been described in detail, it is not my intention to limit the scope of the invention to that particular embodiment, or otherwise than by the terms of the appended claims.

I claim:

1. A brake comprising, in combination, a drum, a backin plate, shoes between the drum and backing plate, a pivot member connecting adjacent shoes and having a head slidably engaging the backing plate, a pivoted positioning lever engaged by thehead of the pivot, and means for swinging the lever to adjust the position of the pivot.

2. A brake comprising, in combination, a drum, a backing plate, shoes between the drum and backing plate, a pivot connecting adjacent shoes and having a head slidably engaging the backingg plate, a movable positioning member engaged by the head of the pivot, and means for adjusting the position of said member.

3. A brake comprising, in combination, a

drum,abacking plate, shoes between the drum and backing plate, a pivot connecting adjacent shoes, a pivoted lever predetermining the idle position of the pivot, and means for changing the position of the lever to adjust the position of the pivot. 4. A brake comprising, in combination, a drum, a friction device engageable with the drum, a part projecting laterally from and movable with the device, a pivoted stop lever engaged by said part, and means for swinging the lever to adjustthe position of said part."

5. A brake comprising, in combination, a drum, a friction device engageable with the drum, a part projectingin a direction paralleling the drum axis from the device, a movable stop member slidably engaged by said pzrt, and means for moving said stop memr to ad ust the position of said part.

6. A brake comprising, in combination, a drum, a friction device engageable with the drum, a part projecting in a direction paralleling the drum axis from the device, a movable stop member slidably engaged by said part, means for moving said stop member to adjust the position of said part, and a spring urging said part toward the stop member.

7. A brake comprising, in combination, a drum, a support plate, a plurality of shoes having a pivotal connection and anchoring on one shoe when the drum is turning in one direction and on a different shoe when the drum is turning in the other direction, and a positioning device comprising a lever mem ber pivoted to said support plate and contacting said pivotal connection.

8. A brake comprising, in combination, a drum, a support plate, a plurality of shoes having a pivotal connection and anchoring on one shoe when the drum is turning in one direction and on a difi'erent shoe when the drum is turning in the other direction, and a positioning device comprising a lever member pivoted to said'support plate and contacting said pivotal connection, said lever member being adjustable with respect to said plate by means contacting one of its ends.

9. Abrake comprising, in combination, a drum, 9. support plate, a plurality of shoes having apivotal connection and anchoring on one shoe when the drum is turning in one direction and on a different shoe when the drum is turning inthe other direction, and a positioning device comprising a lever member disconnectedly engaging said pivotal connection.

10. A brake comprising, in combination, a drum, a backing plate, shoes between the drum and backing plate, a pivot connecting adjacent shoes and a relatively narrow and straight positioning lever member engaging said pivot.

11. A brake comprising, in combination, a drum, a friction device engageable with the drum, 2. part projecting laterally from the device, a curved stop lever pivoted at one end and engaged by said part, the center of curvature of said lever substantially coinciding with the axis of said drum, together with an adjustable stop engaged by the unpivot'ed'end of said lever.

12. A brake comprising, in combination, a drum, a support plate, an expansible friction device within said drum and a positioning device for said friction device comprising a lever member pivoted to said support plate and contacting said friction device, together with applying means acting on the friction device independently of the positioning device.

13. A brake comprising, in combination, a drum, 3. support plate, a plurality of shoes within the drum, a floating pivot forming a ennon connection between adjacent ends of the shoes, a lever pivotally mounted on said plate and forming no part of the connection between the shoes'and which is engaged by said pivot, a fixed stop engaging said lever, and y'ieldable means engagingsaid shoes urging the pivot into contact with said lever.

14;. A brake comprising, in combination, a drum, friction means yvithin the drum and positioning means for said friction means comprising a lever member slidingl contacting said friction means, together with applying means independent of said means. v

In testimony whereof, I have hereunto signed my name.

ABEL Y. DODGE J positioning 

